Rocket

The rocket itself is the heart and soul any sounding rocket program. Hydra-Sandhawk was somewhat different in that there was almost as much work involved in designing and producing the launcher, launcher electronics, handling dolly and preliminary testing as there was in developing and producing the rocket itself.

The Hydra-Sandhawk rocket should have probably been called Hydra-TE-M-473 because the program did not actually use a Sandhawk sounding rocket. It did use the Sandhawk’s long burning Thiokol rocket motor, designated the “TE-M- 473” and none of the other Sandhawk hardware. But, who would ever remember a sounding rocket named Hydra-TE-M-473?

Hydra-Iris, the Hydra-Sandhawk’s predecessor, had a number of limitations including using three Sparrow missile rocket motors, strapped together in parallel for the booster. That rocket design had a number of mechanical and performance limitations plus the added difficulty of trying to ignite three rocket motors simultaneously that had been underwater for eight hours.

The big NOTS 401A motor used on Hydra-Sandhawk had significantly more total impulse and obviously was much simpler and more reliable to use than three Sparrow missile motors. The Thiokol TE-M-473 second stage motor was a definite performance improvement over the old Iris rocket motor. The old Iris rocket motor was a limited production design with less performance, that had to use a very wide three-fin configuration because of the three booster motor configuration. So, the Hydra-Sandhawk was a more conventional sounding rocket using more easily available motors and able to lift much heavier payloads to 170 miles altitude than its predecessor.